Functionalization of tumor necrosis factor-alpha using phage display technique and PEGylation improves its antitumor therapeutic window.
Shibata H,
Yoshioka Y,
Ikemizu S,
Kobayashi K,
Yamamoto Y,
Mukai Y,
Okamoto T,
Taniai M,
Kawamura M,
Abe Y,
Nakagawa S,
Hayakawa T,
Nagata S,
Yamagata Y,
Mayumi T,
Kamada H,
Tsutsumi Y.
Department of Biopharmaceutics, Graduate School of Pharmaceutical Sciences, Osaka University, Osaka, Japan.
PURPOSE: In this study, the optimization of antitumor therapy with tumor necrosis factor-alpha (TNF-alpha) was attempted. EXPERIMENTAL DESIGN: Using the phage display technique, we created a lysine-deficient mutant TNF-alpha (mTNF-K90R). This mutant had higher affinities to both TNF receptors, despite reports that certain lysine residues play important roles in trimer formation and receptor binding. RESULTS: The mTNF-K90R showed an in vivo therapeutic window that was 13-fold higher than that of the wild-type TNF-alpha (wTNF-alpha). This was due to the synergistic effect of its 6-fold stronger in vitro bioactivity and its 2-fold longer plasma half-life derived from its surface negative potential. The reason why the mTNF-K90R showed a higher bioactivity was understood by a molecular modeling analysis of the complex between the wTNF-alpha and TNF receptor-I. The mTNF-K90R, which was site-specifically mono-PEGylated at the NH2 terminus (sp-PEG-mTNF-K90R), had a higher in vitro bioactivity and considerably longer plasma half-life than the wTNF-alpha, whereas the randomly mono-PEGylated wTNF-alpha had 6% of the bioactivity of the wTNF-alpha. With regard to effectiveness and safety, the in vivo antitumor therapeutic window of the sp-PEG-mTNF-K90R was 60-fold wider than that of the wTNF-alpha. CONCLUSIONS: These results indicated that this functionalized TNF-alpha may be useful not only as an antitumor agent but also as a selective enhancer of vascular permeability in tumors for improving antitumor chemotherapy.
PMID: 15623605 [PubMed - indexed for MEDLINE]